Preheat the oven to 425°F (220°C). Prepare a 9×13″ baking dish or two 9″ dishes.

Soak the rice in water while prepping the rest.

Trim and peel onions: cut off top and bottom, remove outer layers, score a vertical slit halfway through and boil in water for 10–15 minutes until layers loosen easily. Drain and cool.

Prepare tomato sauce by blending canned tomatoes and whisking with water, tomato paste, lemon juice, salt, and pepper. Set aside.

Heat olive oil in a skillet over medium heat. Sauté diced onion and garlic for 4–5 minutes until softened. Add ground beef and cook until browned.

Stir in grated tomato, tomato paste, drained rice, lemon juice, parsley, mint, salt, pepper, chicken stock paste, and oregano. Simmer for 8–10 minutes until rice begins to soften and absorb liquid. Remove from heat.

Spread a thin layer of tomato sauce in the bottom of the baking dish.

Gently separate onion layers and wrap each layer around about 2 tablespoons of the filling, rolling to overlap edges. Place rolled onions seam‑side down in the dish, fitting snugly.

Pour the remaining tomato sauce over the stuffed onions. Cover with foil and bake for 30 minutes.

Remove foil, baste the onions with cooking juices, and bake uncovered for another 25–30 minutes until onions are tender and slightly caramelized.

Garnish with chopped parsley and serve hot.